Osteosynthesis plates for stabilization of bone fractures typically are applied with bone screws. Traditionally, bone screws compress a plate onto the bone surface to provide stable fixation. More recently, locking plates have been introduced, which typically have threaded receiving holes for positive, angle-stable fixation of locking screws that have a correspondingly threaded screw head. These locked plating constructs can provide more durable fixation than traditional non-locked constructs, particularly in weak osteoporotic bone.
However, the inherent stiffness of locked plating constructs causes two clinical challenges. First, it may alter the load distribution in bone, which may either cause bone resorption in load-shielded regions adjacent to the plate, or bone fracture due to implant-induced stress risers. Second, the high stiffness of an osteosynthesis plate construct suppresses relative displacement between bone fragments; however, such interfragmentary motion is important to promote the natural cascade of fracture healing by callus formation. Therefore, overly stiff locking plate constructs may delay or prevent fracture healing, which may also lead to implant breakage or loss of screw fixation in the bone.